Color-filter substrate assembly, method for manufacturing the color-filter substrate assembly, electro-optical device, method for manufacturing electro-optical device, and electronic apparatus

ABSTRACT

A color-filter substrate assembly  10  includes a substrate  3   b  having a rugged surface, a light-shield layer  7   a  arranged on the substrate  3   b,  and having a rugged surface conformal to the rugged surface of the substrate  3   b,  a reflective layer  5  arranged on the light-shield layer  7   a  and having a rugged surface conformal to the rugged surface of the light-shield layer  7   a,  and a color layer  4  arranged on the substrate  3   b.  The light-shield layer  7   a  has an aperture  8,  and the reflective layer  5   a  has an aperture  6,  and is covered with the color layer  4.  The invention provides a color-filter substrate assembly which is inexpensive, and provides, in the simple structure thereof, excellent functionality with a light-shield function, such as of a black mask, and a scattering function for a reflective-type display when the color-filter substrate assembly is used in an electro-optical device (such as a reflective-type liquid-crystal display device or a transflective-type liquid-crystal display device).

BACKGROUND OF THE INVENTION

[0001] 1. Technical Field

[0002] The present invention relates to a color-filter substrateassembly, a method for manufacturing the color-filter substrateassembly, an electro-optical device, a method for manufacturing theelectro-optical device, and electronic apparatus. More specifically, thepresent invention relates to a color-filter substrate assembly which isinexpensive, and provides excellent functionality with a light-shieldfunction, such as a black mask, and a scattering function for areflective-type display when the color-filter substrate assembly is usedin a liquid-crystal display device (such as a reflective-typeliquid-crystal display device or a transflective-type liquid-crystaldisplay device). The present invention also relates to a method formanufacturing the color-filter substrate assembly, a liquid-crystaldisplay device, a method for manufacturing the liquid-crystal displaydevice, and electronic apparatus.

[0003] 2. Description of the Related Art

[0004] Liquid-crystal display devices are widely used in electronicapparatus such as a mobile telephone or a mobile personal computer.Liquid-crystal display devices having a structure presenting a colordisplay using a color-filter substrate assembly are also widely used.

[0005] In known color-filter substrate assemblies, R (red), G (green),and B (blue) color layers are arranged in a stripe configuration, amosaic configuration, or a delta configuration on the surface of asubstrate formed of glass or plastic (see FIG. 10).

[0006] A so-called transflective-type liquid-crystal display deviceswitches as necessary between a reflective-type display which allowsexternal light such as natural light or room illumination light to enterthe device from a viewer's side of the device and to present a displayby reflecting the light, and a transmissive-type display which allowslight from a light source to enter the device from the side opposite tothe viewer's side to present a display.

[0007]FIG. 11 is a cross-sectional view diagrammatically illustrating aconventional transflective-type active-matrix liquid-crystal displaydevice including a TFD (Thin-Film Diode) as a two-terminal switchingelement.

[0008] Referring to FIG. 11, the liquid-crystal display device includesa liquid-crystal panel 5 formed of a first substrate 51, a secondsubstrate 52, and a sealing member 54 interposed therebetween, a liquidcrystal 53 encapsulated between the two substrates, and a backlight unit6 arranged on the outside of the second substrate 52 of theliquid-crystal panel 5. Arranged on the first substrate 51 are a matrixof pixel electrodes 511 connected to scanning lines (not shown) throughTFDs (not shown) and an alignment layer 512. Arranged on the secondsubstrate 52 are a reflective layer 521 covering most of the secondsubstrate 52. The reflective layer 521 is directly formed on the secondsubstrate 52 fabricated of glass which is etched for frosting, or thereflective layer 521 is formed on a rugged layer (not shown) of anacrylic resin having a rugged surface, or in case of a color display, acolor layer (not shown) is laminated on the surface of the reflectivelayer 521. A planarization layer 522 covering the second substrate 52having the reflective layer 521 formed thereon, a plurality of band-likecounter electrodes 523 extending in a direction intersecting thescanning lines, and an alignment layer 524 are also provided for panel5. In this arrangement, light incident on the first substrate 51 isreflected from the surface of the reflective layer 521 on the secondsubstrate 52 and exits from the first substrate 51. A reflective-typedisplay is thus presented. The reflective layer 521 has apertures 521 arespectively corresponding to pixel electrodes 511. Light emitted fromthe backlight unit 6 is incident on the second substrate 52, passesthrough the apertures 521 a, and exits from the first substrate 51. Atransmissive-type display is thus presented.

[0009] To present a color display on a conventional liquid-crystaldisplay device shown in FIG. 12, a light-shield layer (a black mask or ablack matrix) 525 for defining a color layer formation region andshielding a margin between color layers is formed on the reflectivelayer 521 formed on a light-shield layer 700 or a substrate (not shown),and a color layer 526 is formed in the color layer formation regiondefined by the light-shield layer (black mask or black matrix) 525.

[0010] In the conventional liquid-crystal display device, both thelight-shield layer 700 and the light-shield layer (black mask or blackmatrix) 525 must be formed, thereby not only complicating themanufacturing process and resulting in a cost increase, but also givingrise to a functional problem of a drop in light reflectance due tounwanted light-shield layer (residuals) on the reflective layer.

SUMMARY OF THE INVENTION

[0011] In view of the above problem, the present invention has beendeveloped. It is an object of the present invention to provide acolor-filter substrate assembly which is inexpensive, and provides, inthe simple structure thereof, excellent functionality with thelight-shield function, such as of a black mask, and the scatteringfunction for a reflective-type display when the color-filter substrateassembly is used in a liquid-crystal display device (especially areflective-type liquid-crystal display device or a transflective-typeliquid-crystal display device), and also to provide a method formanufacturing the color-filter substrate assembly, a liquid-crystaldisplay device, a method for manufacturing the liquid-crystal displaydevice, and electronic apparatus.

[0012] To achieve the above object, a color-filter substrate device ofthe present invention includes a substrate, a light-shield layer whichis arranged on the substrate and substantially shields light, areflective layer which is arranged on the light-shield layerandsubstantially reflects light, and a color layer arranged on thereflective layer, wherein the reflective layer includes an aperture.

[0013] Also, a color-filter substrate assembly of the present inventionincludes a substantially transparent substrate, a light-shield layerwhich is arranged on the substrate and substantially shields light, areflective layer which is arranged on the light-shield layer andsubstantially reflects light, and a color layer arranged on thesubstrate, wherein the light-shield layer includes an aperture, andwherein the reflective layer includes an aperture and is covered withthe color layer.

[0014] When the color-filter substrate assembly thus constructed is usedin an electro-optical device (such as a reflective-type liquid-crystaldisplay device or a transflective-type liquid-crystal display device),the color-filter substrate assembly becomes inexpensive and provides, inthe simple structure thereof, excellent functionality with alight-shield function, such as of a black mask, and a scatteringfunction for a reflective-type display.

[0015] Also, a method of the present invention for manufacturing acolor-filter substrate assembly, includes a step of forming alight-shield layer, which substantially shields light, on a substrate, astep of forming a reflective layer, which substantially reflects light,on the light-shield layer, and a step of forming a color layer on thereflective layer, wherein an aperture is formed in the reflective layerin the step of forming the reflective layer.

[0016] Further, a method of the present invention for manufacturing acolor-filter substrate assembly, includes a step of forming alight-shield layer, which substantially shields light, on asubstantially transparent substrate, a step of forming a reflectivelayer, which substantially reflects light, on the light-shield layer, astep of forming a color layer on the substrate, wherein an aperture isformed in the light-shield layer in the step of forming the light-shieldlayer, wherein an aperture is formed in the reflective layer in the stepof forming the reflective layer, and wherein the reflective layer iscovered with the color layer in the step of forming the color layer.

[0017] In the above arrangements, the color-filter substrate assembly isefficiently manufactured at low costs.

[0018] Also, an electro-optical device of the present invention includesa pair of substrates, a light-shield layer which is arranged on one ofthe pair of substrates and substantially shields light, a reflectivelayer which is arranged on the light-shield layer and substantiallyreflects light, and a color layer arranged on the reflective layer,wherein the reflective layer includes an aperture.

[0019] Further, an electro-optical device of the present inventionincludes a pair of substrates, a light-shield layer which is arranged onone of the pair of substrates and substantially shields light, areflective layer which is arranged on the light-shield layer andsubstantially reflects light, and a color layer arranged on thereflective layer, wherein the one of the pair of substrates issubstantially transparent, wherein the light-shield layer includes anaperture, and wherein the reflective layer includes an aperture and iscovered with the color layer.

[0020] In the above arrangements, a low-cost electro-optical device withexcellent functionality results.

[0021] Also, a method of the present invention for manufacturing anelectro-optical device, includes a step of forming a light-shield layer,which substantially shields light, on a substrate, a step of forming areflective layer, which substantially reflects light, on thelight-shield layer, and a step of forming a color layer on thereflective layer, wherein an aperture is formed in the reflective layerin the step of forming the reflective layer.

[0022] Further, a method of the present invention for manufacturing anelectro-optical device, includes a step of forming a light-shield layer,which substantially shields light, on a substantially transparentsubstrate, a step of forming a reflective layer, which substantiallyreflects light, on the light-shield layer, and a step of forming a colorlayer on the substrate, wherein an aperture is formed in thelight-shield layer in the step of forming the light-shield layer,wherein an aperture is formed in the reflective layer in the step offorming the reflective layer and wherein the reflective layer is coveredwith the color layer in the step of forming the color layer.

[0023] In the above arrangements, an electro-optical device withexcellent functionality is manufactured at low costs.

[0024] Also, electronic apparatus of the present invention includes oneof the above-referenced electro-optical devices.

[0025] In the above arrangements, low-cost electronic apparatus withexcellent functionality is provided.

BRIEF DESCRIPTION OF THE DRAWINGS

[0026]FIG. 1 is a cross-sectional view diagrammatically illustrating oneembodiment of the color-filter substrate assembly of the presentinvention (a first embodiment).

[0027]FIG. 2 is a cross-sectional view diagrammatically illustrating oneembodiment of the color-filter substrate assembly of the presentinvention (a second embodiment).

[0028]FIG. 3 is a cross-sectional view diagrammatically illustrating oneembodiment of the color-filter substrate assembly of the presentinvention (a third embodiment).

[0029]FIG. 4 diagrammatically illustrates process steps of thecolor-filter substrate assembly in cross section and a method formanufacturing the color-filter substrate assembly in accordance with oneembodiment of the present invention (a fourth embodiment).

[0030]FIG. 5 diagrammatically illustrates process steps of thecolor-filter substrate assembly in cross section and a method formanufacturing the color-filter substrate assembly in accordance with oneembodiment of the present invention (a fifth embodiment).

[0031]FIG. 6 diagrammatically illustrates process steps of thecolor-filter substrate assembly in cross section and a method formanufacturing the color-filter substrate assembly in accordance with oneembodiment of the present invention (a sixth embodiment).

[0032]FIG. 7 is a cross-sectional view diagrammatically illustrating anelectro-optical device in accordance with one embodiment of the presentinvention (a seventh embodiment).

[0033]FIG. 8 is a perspective view diagrammatically illustrating a pixeland its surrounding structure in a first substrate of theelectro-optical device illustrated in FIG. 7.

[0034]FIG. 9 is a plan view diagrammatically illustrating the structureof a reflective layer in the electro-optical device illustrated in FIG.7.

[0035] FIGS. 10(a), 10(b), and 10(c) are plan views illustrating thelayout pattern of the pixels of R (red), G (green), and B (blue) colorsin the color filter (color layer).

[0036]FIG. 11 is a cross-sectional view diagrammatically illustrating aconventional transflective-type liquid-crystal display device.

[0037]FIG. 12 is a cross-sectional view diagrammatically illustrating alight-shield layer (a black mask or a black matrix) used in aconventional liquid-crystal display device.

[0038]FIG. 13 is a cross-sectional view diagrammatically illustrating amodification of the embodiment (the third embodiment) of thecolor-filter substrate assembly.

[0039]FIG. 14 diagrammatically illustrates process steps of thecolor-filter substrate assembly in cross section and the method formanufacturing the color-filter substrate assembly in accordance with amodification of the embodiment of the present invention (the sixthembodiment).

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0040] The embodiments of the present invention are discussed withreference to the drawings. The embodiments are discussed below forexemplary purposes only, and are not intended to limit the presentinvention, and modifications thereof are possible without departing fromthe scope of the present invention.

[0041] (First Embodiment)

[0042] Referring to FIG. 1, a color-filter substrate assembly 10 in afirst embodiment includes a substrate 3, a light-shield layer 7 which isarranged on the substrate 3 and substantially shields light, areflective layer 5 which is arranged on the light-shield layer 7 andsubstantially reflects light, and a color layer 4 arranged on thereflective layer 5. The reflective layer 5 has an aperture 6 and iscovered with the color layer 4.

[0043] Referring to FIG. 1, spacing is allowed between adjacent colorlayers 4. Alternatively, adjacent color layers 4 may be contiguous toeach other. In the perspective view thereof from above, the aperture 6surrounds each pixel region. The same is true of the followingembodiments.

[0044] Since the reflective layer 5 has the aperture 6 in this way, thelight-shield layer 7 is exposed so that the contrast of the light-shieldlayer 7 is improved.

[0045] In this arrangement, light from the outside is reflected from thereflective layer 5, and the reflected light presents an image (in areflective-type display). The color-filter substrate assembly 10 thusprovides excellent functionality and is appropriately used as acolor-filter substrate assembly in a low-cost reflective-type displaydevice.

[0046] The present invention will be discussed more in detail.

[0047] There is no particular limitation to the material of thesubstrate 3 in the present invention. A planar member having lighttransmittance, fabricated of glass, quarts or plastic, may be used.However, it is not required in this embodiment that the substrate 3having light transmittance be used.

[0048] The color layer 4 includes R (red), G (green), and B (blue) colorlayers formed in color layer formation regions on the substrate 3 in apredetermined layout pattern, such as a stripe configuration, a mosaicconfiguration, or a delta configuration (see FIG. 10). Specifically, thecolor layer 4 is formed in a color-layer formation region on thesubstrate 3 by applying a predetermined color resin material such as anacrylic resin, into which a R (red) pigment, for example, is dispersed,using a spin coating method or an ink-jet method and then using apredetermined patterning method (a photolithographic process, forexample). In this case, the two-dimensional size of each color-layerformation region is as large as 30 μm×100 μm.

[0049] Also, the reflective layer 5 is a film that reflects lightentering from the outside. For example, the reflective layer 5 is formedof a film fabricated of a material having light reflectance (such asaluminum, silver, or an alloy thereof, or a laminate thereof with atitanium film, a titanium nitride film, a molybdenum film, or a tantalumfilm).

[0050] In addition, the light-shield layer is used to increase thecontrast of an image (using the light-shield function of the blackmatrix). In accordance with the present invention, the light-shieldlayer 7 also has the function of scatting light for the reflective-typedisplay.

[0051] The light-shield layer 7 is fabricated of a resin thatsubstantially shields light. Available as such a light-shield resin isan epoxy resin into which a black pigment is dispersed.

[0052] (Second Embodiment)

[0053] Referring to FIG. 2, the color-filter substrate assembly 10 in asecond embodiment includes a substrate 3 a which is substantiallytransparent, a light-shield layer 7 arranged on the substrate 3 a, areflective layer 5 arranged on the light-shield layer 7, and a colorlayer 4 arranged on the substrate 3 a. The light-shield layer 7 hasapertures 8, and the reflective layer 5 has apertures 6 and is coveredwith the color layer 4.

[0054] Since the light-shield layer 7 has the apertures 8, incidentlight from the backlight passes through the aperture 8, and transmitsthrough the color layer 4. The transmitted light thus presents an image(in the transmissive-type display). With the reflective-type displaywith the reflective layer 5, the color-filter substrate assemblyappropriately finds application in a low-cost transflective-type displaydevice having excellent functionality. This embodiment employs asubstantially transparent substrate 3 a, and the rest of theconstruction remains unchanged from that of the first embodiment.

[0055] (Third Embodiment)

[0056] Referring to FIG. 3, the color-filter substrate assembly 10 in athird embodiment employs a substrate 3 b having a rugged surface insteadof the substrate 3 a in the second embodiment. Furthermore, instead ofthe light-shield layer 7 and the reflective layer 5, a light-shieldlayer 7 a and a reflective layer 5 a, each having a rugged surface, areused. Specifically, the color-filter substrate assembly 10 of the thirdembodiment includes the substrate 3 b which is substantially transparentand has a rugged surface, the light-shield layer 7 a arranged on thesubstrate 3 b, and having the rugged surface conformal to the ruggedsurface of the substrate 3 b, the reflective layer 5 a arranged on thelight-shield layer 7 a and having the rugged surface conformal to therugged surface of the light-shield layer 7 a, and a color layer 4arranged on the substrate 3 b. The light-shield layer 7 a has apertures8, and the reflective layer 5 a has apertures 6 and is covered with thecolor layer 4.

[0057] Instead of the substrate, the light-shield layer and thereflective layer used in the second embodiment, the substrate, thelight-shield layer and the reflective layer in the first embodiment maybe used with the surfaces thereof that have been roughened (sometimesrefered to herein as ruggedized), although they are not particularlyshown.

[0058] In this arrangement, the light-shield layer 7 a having the ruggedsurface conformal to the rugged surface of the substrate 3 b is formed,and the reflective layer 5 a having the rugged surface be conformal tothe rugged surface of the light-shield layer 7 a is formed. Thelight-shield layer 7 a and the reflective layer 5 a, each having therugged surface, are easily produced. With the rugged surface createdthereon, the reflective layer 5 a appropriately scatters light reflectedtherefrom. Optical characteristics are thus improved.

[0059] As shown in FIG. 13, the color-filter substrate assembly 10 mayemploy a substrate 3 b having no rugged surface, instead of a substrate3 b having a rugged surface. A light-shield layer 7 a having a ruggedsurface may be directly formed on the substrate 3 b, and a reflectivelayer 5 a having a rugged surface conformal to the rugged surface of thelight-shield layer 7 a may be formed. This arrangement provides the sameeffect as that discussed above and eliminates a process step for formingthe rugged surface on the substrate. The manufacturing process is thussimplified. Since the rugged surface is selectively formed on thelight-shield layer 7 a, the flexibility of design is widened. Thelight-shield layer 7 a is left with no rugged surface formed in a regionthereof where no rugged surface is desired.

[0060] (Fourth Embodiment)

[0061] Referring to FIG. 4, a method for manufacturing a color-filtersubstrate assembly in accordance with a fourth embodiment includes astep of forming the light-shield layer 7, by applying a substantiallylight-shield resin, such as an epoxy resin in which a black pigment isdispersed, on the substrate 3 through the spin coating process, and byremoving unwanted portions thereof (a light-shield layer formationstep), a step of forming the reflective layer 5 on the light-shieldlayer 7 through the sputtering process (a reflective layer formationstep), a step of forming the aperture 6 on the reflective layer 5through the photolithographic process and the etching process (anaperture formation process on the reflective layer), and a step offorming the color layer 4 on the reflective layer 5 (a color layerformation step).

[0062] In this arrangement, a color-filter substrate assembly for use ina reflective-type display device having excellent functionality isefficiently manufactured at low costs.

[0063] (Fifth Embodiment)

[0064] Referring to FIG. 5, a method for manufacturing a color-filtersubstrate assembly in accordance with a fifth embodiment includes a stepof forming the light-shield layer 7, by applying a substantiallylight-shield resin, such as an epoxy resin in which a black pigment isdispersed, on the substantially transparent substrate 3 a through a spincoating process, and by removing unwanted portions thereof, a step offorming the aperture 8 on the light-shield layer 7 through thephotolithographic process (an aperture formation step on thelight-shield layer), a step of forming the reflective layer 5 on thelight-shield layer 7 through the sputtering process (a reflective layerformation step), a step of forming the aperture 6 on the reflectivelayer 5 through the photolithographic process and the etching process(an aperture formation step on the reflective layer), and a step ofcovering the reflective layer 5 on the substrate 3 a with the colorlayer (a color layer formation step).

[0065] In this arrangement, a color-filter substrate assembly havingexcellent functionality and for use in a transflective-type displaydevice is efficiently manufactured at low costs.

[0066] (Sixth Embodiment)

[0067] Referring to FIG. 6, a sixth embodiment of the present inventionadditionally includes a rugged surface formation step to be discussedlater in the method for manufacturing the color-filter substrateassembly in accordance with the fifth embodiment of the presentinvention.

[0068] Specifically, a method for manufacturing a color-filter substrateassembly in accordance with the sixth embodiment of the presentinvention includes a step of forming the substrate 3 b having the ruggedsurface by ruggedizing the surface of the substantially transparentsubstrate 3 a through the etching process (a rugged surface formationstep on the substrate), a step of forming the light-shield layer 7 ahaving a surface configuration conformal to the rugged surface of thesubstrate 3 b, by applying a substantially light-shield resin, such asan epoxy resin in which a black pigment is dispersed, on the substrate 3b having the rugged surface through the spin coating process, and byremoving unwanted portions thereof, a step of forming the aperture 8 onthe light-shield layer 7 a through the photolithographic process (anaperture formation step on the light-shield layer), a step of formingthe reflective layer 5 a having the configuration conformal to therugged surface of the light-shield layer 7 a on the light-shield layer 7a through the sputtering process (a reflective layer formation step), astep of forming the aperture 6 on the reflective layer 5 a through thephotolithographic process and the etching process (an aperture formationstep on the reflective layer), and a step of covering the reflectivelayer 5 a on the substrate 3 b with the color layer (a color layerformation step).

[0069] In this case, the rugged surface formation step may be skipped.Specifically, referring to FIG. 14, the light-shield layer 7 having arugged surface may be directly formed on the substrate 3 b having norugged surface through the photolithographic process and the etchingprocess, and the reflective layer 5 a having a surface configurationconformal to the rugged surface of the light-shield layer 7 a may beformed on the light-shield layer 7 a. This arrangement provides the sameeffect as that discussed above and eliminates a process step for formingthe rugged surface on the substrate. The manufacturing process is thussimplified. Also, since the rugged surface is selectively formed on thelight-shield layer 7 a, the flexibility of design is widened. Thelight-shield layer 7 a is left with no rugged surface formed in a regionthereof where no rugged surface is desired.

[0070] In this arrangement, a color-filter substrate assembly havingexcellent functionality and for use in a transflective-type displaydevice is efficiently manufactured at low costs.

[0071] The above-mentioned rugged surface formation step on thesubstrate may be added to the method for manufacturing the color-filtersubstrate assembly in accordance with the fourth embodiment, althoughthe process therefor is not illustrated here. Specifically, the surfaceof the substrate in the fourth embodiment may be ruggedized in therugged surface formation step on the substrate, and the light-shieldlayer and the reflective layer in the fourth embodiment may also beruggedized.

[0072] The reflective layer formation step will be detailed in theembodiment of the electronic apparatus of the present invention.

[0073] (Seventh Embodiment)

[0074] Referring to FIG. 7, an electro-optical device (as anactive-matrix transflective-type liquid-crystal display device employinga two-terminal switching element) in a seventh embodiment includes apair of substrates 11 and 12, a light-shield layer 107 which is arrangedon one of the pair, namely, on the substrate 12 and substantiallyshields light, a reflective layer 105 which is arranged on thelight-shield layer 107 and substantially reflects light, and a colorlayer 104 arranged on the reflective layer 105. The reflective layer 105has apertures 106. The light-shield layer 107, the reflective layer 105and the color layer 104 arranged on the substrate 12 may have any of thestructures illustrated in FIG. 1 through FIG. 3.

[0075] The electro-optical device is discussed further in detail.

[0076] Referring to FIG. 7, the electro-optical device in the seventhembodiment includes a liquid-crystal panel 1 including a liquid crystal13 encapsulated between the pair of substrates (the first substrate 11and the second substrate 12) opposed to each other with a sealing member(not shown) interposed therebetween, and a backlight unit 2 arranged onthe second substrate 12 (the one of the pair of substrates) of theliquid-crystal panel 1. Although in practice, a polarizer for polarizingincident light and a retardation film are glued onto the outer surfaceof each of the first substrate 11 and the second substrate 12 (the sideopposite from the liquid crystal 13), these components are neitherillustrated nor discussed further because the components are not closelyrelated to the present invention.

[0077] The backlight unit 2 includes a linear fluorescent lamp (notshown) for emitting light, a reflector (not shown) for reflecting andguiding the light toward a light guide 21, the light guide 21 forguiding the light from the fluorescent lamp to the entire plane of theliquid-crystal panel 1, a diffuser 22 for uniformly diffusing the lightguided by the light guide 21 to the liquid-crystal panel 1, and areflector 23 for reflecting light emitted from the light guide 21 in adirection opposite from the liquid-crystal panel 1 toward theliquid-crystal panel 1. The fluorescent lamp is not always lit. When noexternal light is available, the fluorescent lamp is lit in response toa command from a user or a detected signal from a sensor to present atransmissive-type display.

[0078] The first substrate 11 in the liquid-crystal panel 1 is a planarmember fabricated of glass, quartz, or plastic, and having lighttransmittance. Arranged on the inner surface of the first substrate 11(facing the liquid crystal 13) is a plurality of pixel electrodes 111 ina matrix. Each pixel electrode 111 is fabricated of an electricallyconductive transparent material such as ITO (Indium Tin Oxide).

[0079]FIG. 8 is an enlarged perspective view of the surface of the firstsubstrate 11 on which the pixel electrodes 111 are arranged. It shouldbe noted that FIG. 8 shows the first substrate 11 shown in FIG. 7 upside down.

[0080] Referring to FIG. 8, the pixel electrode 111 is connected,through a TFD 113, to a scanning line 114 (extending in a directionperpendicular to the page of FIG. 7) for feeding a pixel voltage. TheTFD 113 includes a first metal layer 113 a branching off from thescanning line 114, an oxide layer 113 b, as an insulator, which isformed by anodizing the surface of the first metal layer 113 a, and asecond metal layer 113 c fabricated of chromium on the oxide layer 113b. The TFD 113 is a two-terminal switching element having non-linearcurrent-voltage relationships. The second metal layer 113 c of the TFD113 is connected to the pixel electrode 111.

[0081] Referring to FIG. 7, the surface of the first substrate 11 havingthe pixel electrode 111 and the TFD 113 formed thereon is covered withan alignment layer 112. The alignment layer 112 is an organic thin filmsuch as of polyimide, and is subjected to a rubbing process to controlthe alignment direction of the liquid crystal 13 with no voltageapplied.

[0082] The second substrate 12 includes a laminate of the light-shieldlayer 107 formed on the surface of the second substrate 12 fabricated ofglass, etc., the reflective layer 105 formed on the light-shield layer107 and having the apertures 106, and the color filter (color layer) 104covering the reflective layer 105. Furthermore, an overcoat layer 124,counter electrodes 125, and an alignment layer 126 are laminated.

[0083] As already described, the reflective layer 105 is fabricated of amaterial (such as aluminum or silver) having light reflectance, and isused to reflect light incident on the first substrate 11.

[0084]FIG. 9 is a plan view diagrammatically illustrating the pattern ofthe reflective layer 105. Referring to FIG. 9, a region of thereflective layer 105 facing each pixel electrode 111 of the firstsubstrate 11 is represented by a dotted line. Referring to FIG. 9, thereflective layer 105 is formed to generally cover the surface of thesecond substrate 12 except the aperture 106, which is a portion of theregion facing each pixel electrode 111 in the first substrate 11. Aswill be discussed later, light incident on the backlight unit 2 ispassed through the aperture 106 of the reflective layer 105, and is thenoutput from the first substrate 11 to present a transmissive-typedisplay.

[0085] The region of the inner surface of the second substrate 12(specifically, the surface of the light-shield layer 107) covered withthe reflective layer 105 (hereinafter referred to a reflective region)has a surface roughness with a fine ruggedness. For this reason, thereflective layer 105 has a rugged surface conformal to the ruggedsurface of the reflective region.

[0086] The color filter (color layer) 104 is a film formed of a resinmaterial colored with R (red), G (green), or B (blue) pigment or dye asalready described. The second substrate 12 having the reflective layer105, the light-shield layer 107 and color filter (color layer) 104formed thereon is covered with the overcoat layer 124 fabricated of anacrylic resin or an epoxy resin. The overcoat layer 124 planarizesprojections formed on the second substrate 12 with the light-shieldlayer 107, the reflective layer 105, and the color filter (color layer)104 while preventing the liquid crystal from being degraded by leaks ofan organic material into the liquid crystal out of the color filter(color layer) 104.

[0087] Further, a plurality of counter electrodes 125 is formed on theovercoat layer 124. Each counter electrode 125 is a band-like electrodeextending in a predetermined direction and facing each of the pluralityof pixels 111 lined on the first substrate 11. The counter electrode 125is fabricated of an electrically conductive transparent material such asITO. The liquid crystal 13 encapsulated between the first substrate 11and the second substrate 12 changes the alignment direction thereof whena voltage is applied between the pixel electrode 111 and the counterelectrode 125. In other words, the region where each pixel electrode 111faces the counter electrode 125 functions as a pixel.

[0088] The aperture 106 of the reflective layer 105 is formed in an areawhere no light-shield resin layer 12 b is formed. The surface of theovercoat layer 124 having the counter electrodes 125 thereon is coveredwith the alignment layer 126 as the pixel electrodes 111 are coveredwith the alignment layer 112.

[0089] In the above arrangement, the reflective-type display and thetransmissive-type display are presented.

[0090] In the reflective-type display, the external light such assunlight or room illumination light is incident on the first substrate11, travels along a path through the first substrate 11, the pixelelectrode 111, the alignment layer 112, the liquid crystal 13, thealignment layer 126, the counter electrode 125, the overcoat layer 124,and the color filter 104, and then reaches the reflective layer 105. Thelight is then reflected from the reflective layer 105, travels in theopposite direction along the above incoming path, exits from the firstsubstrate 11, and is then observed by the viewer. As described above,the reflective layer 105 has the rugged surface conformal to the ruggedsurface of the reflective region of the second substrate 12. For thisreason, the incident light on the first substrate 11 is reflected fromthe reflective layer 105 while being scattered from the rugged surfaceof the reflective layer 105, and is then exits from the first substrate11. In this arrangement, a scene behind the viewer and the image of theroom illumination light are prevented from being reflected.

[0091] When the transmissive-type display is presented on the otherhand, the light from the backlight unit 2 travels along a path throughthe second substrate 12, the aperture 8 of the light-shield layer 107,the aperture 122 of a reflective layer 121, a color filter (color layer)123, the overcoat layer 124, the counter electrode 125, the alignmentlayer 126, the liquid crystal 13, the alignment layer 112, the pixelelectrode 111, and the first substrate 11, and then reaches the viewer.

[0092] (Eighth Embodiment)

[0093] A method of an eighth embodiment of the present invention formanufacturing an electro-optical device, includes a step of forming alight-shield layer, which substantially shields light, on a substrate (alight-shield layer formation step), a step of forming a reflectivelayer, which substantially reflects light, on the light-shield layer (areflective layer formation step), and a step of forming an aperture onthe reflective layer (an aperture formation step on the reflectivelayer), and a step of forming a color layer on the reflective layer (acolor layer formation step).

[0094] (Ninth Embodiment)

[0095] A method of a ninth embodiment of the present invention formanufacturing an electro-optical device, includes a step of forming alight-shield layer, which substantially shields light, on asubstantially transparent substrate (a light-shield layer formationstep), a step of forming an aperture on the light-shield layer (anaperture formation step on the light-shield layer), a step of forming areflective layer, which substantially reflects light, on thelight-shield layer (a reflective layer formation step), a step offorming an aperture on the reflective layer (an aperture formation stepon the reflective layer), and a step of forming a color layer to coverthe reflective layer on the substrate (a color layer formation step).

[0096] The above process steps have been already discussed and thediscussion thereof is skipped here. Process steps subsequent to theabove process steps are discussed below with reference to FIG. 7.

[0097] Subsequent to the above process steps, a resin material such asan acrylic resin is applied on the entire surface of the secondsubstrate 12, and is then fired to form the overcoat layer 124. An ITOthin film is arranged on the surface of the overcoat layer 124 throughthe sputtering process. The ITO film is then subjected to thephotolithographic process and the etching process to form a plurality ofband-like counter electrodes 125. An organic material such as polyimideis applied on the overcoat layer 124 having the counter electrodes 125formed thereon and is then fired to form the alignment layer 126. Thealignment layer 126 is then subjected to an axis alignment process inaccordance with a twist angle of the liquid crystal 13 (such as arubbing process).

[0098] The scanning line 114, the TFD 113, and the pixel electrode 111are formed on the first substrate 11. Each of these elements may beproduced using any known technique.

[0099] A sealing member surrounding the outline of the second substrate12 is printed on the second substrate 12 thus constructed. The firstsubstrate 11 having the pixel electrodes 111 formed thereon is bonded tothe second substrate 12 with the sealing member interposed therebetween.The liquid-crystal panel 1 is then obtained by encapsulating the liquidcrystal 13 between the two substrates. The backlight unit 2 is thenarranged behind the second substrate 12 of the liquid-crystal panel 1,and then the electro-optical device shown in FIG. 7 is completed.

[0100] The embodiments of the electro-optical device of the presentinvention have been discussed for exemplary purposes only. Theabove-referenced embodiments may be modified without departing from thescope and spirit of the present invention. The following modificationsare contemplated.

[0101] In each of the above-referenced embodiments, the liquid-crystaldisplay device is of an active-matrix type with a two-terminal switchingelement. The present invention is applicable to a liquid-crystal displaydevice using a three-terminal switching element such as TFT (Thin-FilmTransistor) and a passive-matrix liquid-crystal display device. As inthe above-referenced embodiments, these electro-optical devices includea light-shield layer, a reflective layer having an aperture, and a colorfilter (a color layer) on one of a pair of substrates encapsulating aliquid crystal therebetween, opposite from the other of the pair facingthe viewer. In each of the above-referenced embodiments, the pixelelectrodes 111 and the TFDs 113 are arranged on the first substrate 11facing the viewer and the counter electrodes 125 are arranged on thesecond substrate 12 opposite from the viewer. Conversely, the counterelectrodes may be arranged on the first substrate 11, and the pixelelectrodes and the switching elements may be arranged on the secondsubstrate 12. When a three-terminal switching element such as a TFT isused, the substrate facing the viewer serves as an element substratebearing the switching elements thereon, and the other substrate is acounter substrate bearing the counter electrodes formed thereon.Conversely, the substrate facing the viewer may be a counter substrateand the substrate arranged opposite from the viewer may be an elementsubstrate.

[0102] The electro-optical device of the present invention may beapplied not only to a liquid-crystal display device but also to anelectroluminescent device, an organic electroluminescent device, aplasma display device, an electrophoretic display device, or afield-emission display device.

[0103] In each of the above-referenced embodiments, the reflective layer105 and the counter electrodes 125 are arranged as separate elements onthe second substrate 12. Alternatively, a reflective electrode servingthe purposes of the reflective layer 105 and the counter electrodes 125at the same time may be used.

[0104] As discussed above, the present invention provides a color-filtersubstrate assembly which is inexpensive, and provides, in the simplestructure thereof, excellent functionality with a light-shield function,such as of a black mask, and a light scattering function for areflective-type display when the color-filter substrate assembly is usedin an electro-optical device (such as a reflective-type liquid-crystaldisplay device or a transflective-type liquid-crystal display device).The present invention also provides a method for manufacturing thecolor-filter substrate assembly, an electro-optical device, a method formanufacturing the electro-optical device, and electronic apparatus.

[0105] The entire disclosures of Japanese patent application numbers2001-239608 filed Aug. 7, 2001 and 2002-195213 filed Jul. 3, 2002 arehereby incorporated by reference.

What is claimed is:
 1. A color-filter substrate assembly comprising: asubstrate, a light-shield layer arranged on the substrate, a reflectivelayer arranged on the light-shield layer, and a color layer arranged onthe reflective layer, wherein the reflective layer includes an aperture.2. A color-filter substrate assembly comprising: a transparentsubstrate, a light-shield layer arranged on the substrate, a reflectivelayer arranged on the light-shield layer, and a color layer arranged onthe substrate, wherein the light-shield layer includes an aperture, andwherein the reflective layer includes an aperture and is covered withthe color layer.
 3. A color-filter substrate assembly according to claim1, wherein the substrate comprises a roughened portion on the surfacethereof.
 4. A color-filter substrate assembly according to claim 1,wherein the light-shield layer comprises a roughened portion on thesurface thereof.
 5. A color-filter substrate assembly according to claim1, wherein the reflective layer comprises a roughened portion on thesurface thereof.
 6. A method for manufacturing a color-filter substrateassembly, comprising: a step of forming a light-shield layer on asubstrate, a step of forming a reflective layer on the light-shieldlayer, and a step of forming a color layer on the reflective layer,wherein an aperture is formed in the reflective layer in the step offorming the reflective layer.
 7. A method for manufacturing acolor-filter substrate assembly, comprising: a step of forming alight-shield layer on a transparent substrate, a step of forming areflective layer on the light-shield layer, a step of forming a colorlayer on the substrate, wherein an aperture is formed in thelight-shield layer in the step of forming the light-shield layer,wherein an aperture is formed in the reflective layer in the step offorming the reflective layer, and wherein the reflective layer iscovered with the color layer in the step of forming the color layer. 8.A method for manufacturing a color-filter substrate assembly accordingto claim 7, further comprising a step of forming a roughened portion onthe surface of the substrate.
 9. A method for manufacturing acolor-filter substrate assembly according to claim 8, wherein aroughened portion is formed on the surface of the light-shield layer inthe step of forming the light-shield layer.
 10. A method formanufacturing a color-filter substrate assembly according to claim 9,wherein a roughened portion is formed on the surface of the reflectivelayer in the step of forming the reflective layer.
 11. A method formanufacturing a color-filter substrate assembly according to claim 10,wherein the light-shield layer is manufactured of a resin in the step offorming the light-shield layer.
 12. An electro-optical devicecomprising: a pair of substrates, a light-shield layer arranged on oneof the pair of substrates, a reflective layer arranged on thelight-shield layer, and a color layer arranged on the reflective layer,wherein the reflective layer includes an aperture.
 13. Anelectro-optical device comprising: a pair of substrates, a light-shieldlayer arranged on one of the pair of substrates, a reflective layerarranged on the light-shield layer, and a color layer arranged on thereflective layer, wherein the one of the pair of substrates istransparent, wherein the light-shield layer comprises an aperture, andwherein the reflective layer includes an aperture and is covered withthe color layer.
 14. An electro-optical device according to claim 13,wherein the one of the pair of substrates has a roughened rugged portionon the surface thereof.
 15. An electro-optical device according to claim14, wherein the light-shield layer has a roughened portion on thesurface thereof.
 16. An electro-optical device according to claim 15,wherein the reflective layer has a roughened portion on the surfacethereof.
 17. Electronic apparatus comprising an electro-optical deviceaccording to claim
 16. 18. A method for manufacturing an electro-opticaldevice, comprising: a step of forming a light-shield layer on asubstrate, a step of forming a reflective layer on the light-shieldlayer, and a step of forming a color layer on the reflective layer,wherein an aperture is formed in the reflective layer in the step offorming the reflective layer.
 19. A method for manufacturing anelectro-optical device, comprising: a step of forming a light-shieldlayer on a transparent substrate, a step of forming a reflective layeron the light-shield layer, and a step of forming a color layer on thesubstrate, wherein an aperture is formed in the light-shield layer inthe step of forming the light-shield layer, wherein an aperture isformed in the reflective layer in the step of forming the reflectivelayer, and wherein the reflective layer is covered with the color layerin the step of forming the color layer.
 20. A method for manufacturingan electro-optical device claim 19, further comprising a step of forminga roughened portion on the surface of the substrate.
 21. A method formanufacturing an electro-optical device according to claim 20, wherein aroughened portion is formed on the surface of the light-shield layer inthe step of forming the light-shield layer.
 22. A method formanufacturing an electro-optical device according to claim 21, wherein aroughened portion is formed on the surface of the reflective layer inthe step of forming the reflective layer.
 23. A method for manufacturingan electro-optical device according to claim 22, wherein thelight-shield layer is manufactured of a resin in the step of forming thelight-shield layer.